종방향 전기장 근접 감지 방식 수액 주입 측정 센서

김영철 ( Young Cheol Kim ),세이크파이잘아마드 ( Sheikh Faisal Ahmad ),김현덕 ( Hyun Deok Kim ) 한국센서학회 2017 센서학회지 Vol.26 No.2

A novel intravenous (IV) infusion monitoring sensor is presented to measure the drop rate in the drip chamber of an IV infusion set. It is based on a capacitive proximity sensor and detects the variation of the longitudinal electric field induced by the drop falling into the drip chamber. Unlike the conventional capacitor sensor with two semi-cylindrical conductor plates, the proximity sensor for IV monitoring is composed of a pair of conductor rings which are mounted on the outer surface of the drip chamber with a specific gap between them. The characteristics of the proximity sensor for IV monitoring were investigated through three dimensional electrostatic simulations. It showed quite superior performances in comparison with the conventional capacitor sensor. Especially, the proposed proximity sensor exhibits consistent sensitivity regardless of its mounting position on the drip chamber, operates normally though the drip chamber is tilted and shows robustness to the changes of the drop size and the drip factor of the IV infusion set. Thus, the proximity sensor for IV monitoring is more suitable for use in actual environment of IV therapy compared with the conventional capacitor sensor.

입사광량의 조절과 이에 따른 비분산 적외선 알코올 센서의 온도 특성과 보정

김진호 ( Jinho Kim ),조희찬 ( Heechan Cho ),이승환 ( Seunghwan Yi ) 한국센서학회 2018 센서학회지 Vol.27 No.1

In this paper, we describe the thermal characteristics of the output voltages of ethanol gas sensor according to the amount of radiation incident on the infrared sensors located at each focal point of two elliptical waveguides. In order to verify the output characteristics of the gas sensor according to the amount of incident light on the infrared sensor, two combinations of sensor modules were fabricated. Hydrophobic thin film is deposited on one of the reflectors of sensor modules and one of the two infrared sensors was equipped with a hollow disk (1.0 Ø), and the temperature characteristics of the infrared sensor equipped with the hollow disk (1.0 Ø) and the infrared sensor without the disk were tested. The temperature was varied from 253 K to 333 K at 10 K intervals based on 298 K. The properties of ethanol gas sensor have been identified with respect to varying temperature for a range of ethanol concentration from 0 ppm to 500 ppm. In the case of an infrared sensor equipped with a hollow disk (1.0 Ø), the output voltage of the sensor decreased by 0.8 mV and 1 mV, respectively, as the temperature increased. Conversely, the output voltage of the diskless infrared sensor showed an average increase of 67 mV and 57 mV as the temperature increased. The ethanol concentrations estimated on the basis of results show an error of more than 10 % for less than 100 ppm concentration. However, if the ethanol concentration exceeds 100 ppm, the gas concentration can be estimated within the range of ±10%.

빔 혹은 멤버레인 구조를 가지는 써모파일 센서의 다목적 최적설계

이준배,김태윤,Lee, Jun-Bae,Kim, Tae-Yoon 한국센서학회 1997 센서학회지 Vol.6 No.1

이 논문은 빔의 구조를 갖거나 멤브레인의 구조를 갖는 써모파일 센서의 다목적 최적설계에 관한 연구이다. 연구대상의 써모파일 센서는 $Si_{3}N_{4}/SiO_{2}$ 박막위에 알루미늄과 다결정 실리콘을 사용하여 열전쌍을 형성하고, 박막중심부에 $RuO_{2}$를 사용하여 적외선 흡수부를 만들어 중심부와 실리콘림부 사이의 온도차이에 따른 Seebeck 효과에 의한 유기전압을 감지하는 센서를 대상으로 하였다. 최적설계의 목적함수는 센서의 감도, 검출능 (detectivity) 및 열시정수를 대상으로 하였다. 패키지를 고려하여 모델링을 하였으며, 기존의 식의 고찰에 의한 단순 설계방법이 아닌 수학적 계획법을 사용한 다목적 최적화 방법을 이용하여 최적해를 구하였다. 최종적인 최적설계 수식화에는 퍼지계획법에서 사용되는 소속함수를 정의하여 설계자가 우선적으로 신뢰할 수 있는 해를 구 할 수 있도록 하였다. 또한, 제한조건으로서 주위 온도변화에 따른 센서의 출력전압변화를 포함시켜 실제 사용되는 환경을 고려하였다. This paper presents the multi-objective optimal design of thermopile sensor having beam or membrane structure. The thermopile sensor is composed of $Si_{3}N_{4}/SiO_{2}$ dielectric membrane, Al-polysilicon thermocouples and $RuO_{2}$ thin film for black body. The sensing method is based on the Seebeck effect which is originated from the temperature difference of the two positions, black body and silicon rim. The objective functions of the presented design are sensitivity, detectivity and thermal time constant. The modelling of the sensor is proposed including the package. The multi-objective optimization technique is applied to the design of the sensor not only inspecting the modelling equation but also simulating mathematical programming method. Especially, fuzzy optimization technique is adapted to get the optimal solution which enables the designer to reach the more practical solution. The design constraint of the voltage output originated from the change of the environmental temperature is included for practical use.

단일전극을 가진 마이크로 가스센서의 제작 및 특성

송갑득,박영일,이상문,이윤수,최낙진,주병수,서무교,허증수,이덕동 한국센서학회 2002 센서학회지 Vol.11 No.6

센서의 안정도와 감도를 개선시킬 수 있는 단일전극을 가진 열선형 마이크로 가스센서를 제작하였다. 일반적으로, 금속산화물 반도체를 이용한 가스센서는 히터전극과 감지전극의 두 개의 전극을 가지고 있다. 제작된 센서는 히터전극위에 감지물질을 형성하여 단일 전극을 가지는 구조를 가지고 있다. 히터와 감지전극으로 사용되는 Pt는 glass 기판위에 스퍼터링법으로 형성하였으며, SnO_2 감지물질은 제작된 Pt 전극위에 열증착시켜 형성하였다. SnO_2막은 lift-off 공정을 이용해서 패턴을 형성하고 1시간 동안 산소분위기에서 열산화하였다. 제작된 소자의 크기는 1.92x.1 mm^2 이다. CO 가스에 대한 감지특성을 조사한 결과 1,000 ppm에 대해 100 mV의 출력변화를 나타내었으며, 넓은 농도범위(0 ~ 10,000 ppm에서 선형적인 전압출력을 나타내었다. 또한 가스 반응 전과 반응 후의 전압출력을 비교해 볼 때, 1 % 이내의 편차를 나타내는 우수한 회복성을 나타내었다. Micro gas sensor with single electrode was proposed for improving stability and sensitivity, Generally, metal oxide gas sensors have two electrodes for heating and sensing. This fabricated new type sensor have only a single electrode by forming a sensing material onto heating electrode. Pt as a heating and sensing electrode was sputtered on glass and a SnO_2 sensing material was thermally evaporated on Pt electrode. SnO_2 was patterned by lift-off process and then thermally oxidized in O_2 condition for 1 hr., 600 ℃. The size fabricated sensor was 1.9 x 2.1 mm^2. As a result of CO gas sensing characteristics, this sensor showed 100 mV change for 1,000 ppm and linearlity for wide range(0 ~ 10,000 ppm) of gas concentrations. And the sensor shows a good recovery characteristics of 1 % deviation compared to initial resistance.

유전체 (Si3N4/SiO2/Si3N4) 멤브레인 위에 제작된 크로멜-알루멜 열전 유량센서

이형주 ( Lee Hyeong Ju ),김진섭 ( Kim Jin Seob ),김여환 ( Kim Yeo Hwan ),이정희 ( Lee Jeong Hui ),최용문 ( Choe Yong Mun ),박세일 ( Park Se Il ) 한국센서학회 2003 센서학회지 Vol.12 No.3

Si₃N₄/SiO₂/Si₃N₄ 열차단막을 이용한 크로멜-알루멜(chromel-alumel) 열전(thermoelectric) 유량센서를 제작하였다. 백금 박막 히터의 저항온도계수는 약 0.00397/℃이었고, 크로멜-알루멜 열전쌍(thermocouple)의 Seebe다 계수는 약 36 μN/K이었다. 기체의 열전도도가 증가할수록 유량센서가 나타내는 열기전력은 감소하였으며, 히터의 온도가 증가하거나 히터와 열전쌍 사이의 간격이 감소할수즉 유량센서의 N₂유량에 대한 심도는 증가하였다. 히터 전압을 약 2.5 V로 하였을 때 유량센서의 N₂ 유량에 대한 감도는 약 1.5 ㎷/sccm^(1/2)이었고, 열 응답시간은 약 0.18초이었다. 크로켈-알루켈 열전 유량센서의 유량감도에 있어서 신형 범위가 Bi-Sb 유량센서의 것보다 더 넓게 나타났다. A chromel-alumel thermoelectric flow sensor using Si₃N₄/SiO₂/Si₃N₄thermal isolation membrane was fabricated. Temperature coefficient of resistance of thin film Pt-heater was about 0.00397/℃, and Seebeck coefficient of chromel-alumel thermocouple was about 36 ㎶/K. The sensor showed that thermoelectric voltage decreased as thermal conductivity of gas increased, and N₂-flow sensitivity increased as heater voltage increased or the distance between heater and thermocouple decreased. When heater voltage was about 2.5 V, N₂-flow sensitivity and thermal response time of the sensor were about 1.5 ㎷/sccm^(1/2) and 0.18 sec., respectively. Linear range in flow sensitivity of the flow sensor was wider than that of Bi-Sb flow sensor.

Fe₂O₃후막을 이용한 alcohol sensor 제작 및 감응특성

이윤수,송갑득,이상문,심창현,최낙진,주병수,이덕동,허증수,Lee, Y.S.,Song, K.D.,Lee, S.M.,Shim, C.H.,Choi, N.J.,Joo, B.S.,Lee, D.D.,Huh, J.S. 한국센서학회 2002 센서학회지 Vol.11 No.2

저비용과 휴대성을 고려한 알코올 경보기의 제작을 위해 동작온도가 낮고 감도가 높은 반도체 가스 센서를 제작하였다. $Fe_2O_3$에 금속 산화물인 $MoO_3$, $V_2O_5$, $TiO_2$, 그리고 CdO 등을 첨가하여 스크린 프린팅법을 이용하여 센서를 제작하였다. 센서의 전기적 안정성을 위하여 질소 분위기에서 $700^{\circ}C$, 2시간 동안 열처리를 하였다. 알코올, 탄화수소계 가스와 담배연기 등을 사용하여 센서의 가스 감도를 조사하였다. $V_2O_5$를 첨가한 센서가 알코올 가스 1,000 ppm에 대해서 약 $80{\sim}90%$의 감도를 보이며, 타 가스에 대한 선택성도 가짐을 알 수 있었다. 제작된 센서와 PIC-chip을 사용하여 휴대 가능한 경보기를 제작할 수 있었다. In order to get low cost and portability, semiconductor gas sensor need to have low operating temperature and high sensitivity. $Fe_2O_3$ based sensors which were doped with metal oxide catalysts($MoO_3$, $V_2O_5$, $TiO_2$, and CdO) were fabricated by screen printing method. To improve electrical stability of sensors, the $Fe_2O_3$ sensors were annealed in $N_2$ at $700^{\circ}C$ for 2 hours. The $V_2O_5$ doped $Fe_2O_3$ sensor showed about $80{\sim}90%$ sensitivity at alcohol 1,000 ppm and have good selectivity to hydrocarbon gas and tobacco odors. The fabricated sensor and PIC-chip were employed for portable alarm system.

정온도형 유속 및 유량 측정센서

박세광,김형표,Park, Se-Kwang,Kim, Hyoung-Pyo 한국센서학회 1992 센서학회지 Vol.29 No.3

기체와 액체의 유숙을 측정하기 위한 반도체 기술을 이용한 소형의 정온도형 유속센서가 제작되었다. 유속센서는 유속에 영향을 받는 대류 열전달만을 검출하도록 설계되었고, 다른 종류의 열전달과 간섭효과는 기준센서의 사용으로 상쇄되도록 하였다. 원리는 유동에 의한 센서 양단전류의 변화로 유속을 측정하는 것이다. 이 유속센서의 실험은 수돗물로 가는 관(지름 8mm)을 사용하여 수행되었다. 그 결과 센서의 소비전력과 유속의 제곱근 사이의 관계는 유속이 0-200cm/sec 범위에서 거의 선형으로 나타났다. A constant temperature type of flow sensor using a solid state micromachining technology was developed for measuring the velocity of gas or liquid. It was designed to detect only the heat convection related to flow velocity. Other heat transfer terms and common mode interferences are canceled by differentiating both reference and exposed flow sensor. It employs the principle that the change of current through the sensing element can be used to measure the flow velocity. An experimental study of the behavior on this flow sensor was performed in a narrow tube(diameter : 8mm) for city water. The relation between power consumption of the flow sensor and square-root of flow velocity is almost linear in the low velocity range(0-200 cm/sec).

편마비 다리환자를 위한 보행보조로봇의 발목 2축 힘센서 설계

최치훈,김갑순,Choi, Chi-Hun,Kim, Gab-Soon 한국센서학회 2017 센서학회지 Vol.26 No.5

This paper describes the design and manufacture of a ankle two-axis force sensor of a walking assist robot for hemiplegic leg patient. The walking assist robot for the hemiplegic leg patient can safely control the robot by detecting whether the foot wearing the walking assist robot is in contact with the obstacle or not. To do so, a two-axis force sensor should be attached to the robot's ankle. The sensor is used to measure the force of a patient's ankle lower part. The two-axis force sensor is composed of a Fx force sensor, a Fy force sensor and a pulley, and they detect the x and y direction forces, respectively. The two-axis force sensor was designed using by FEM(Finite Element Method), and manufactured using by strain-gages. The characteristics experiment of the two-axis force sensor was carried out respectively. The test results indicated that the interference error of the two-axis force sensor was less than 1.2%, the repeatability error and the non-linearity of the two-axis force sensor was less than 0.04% respectively. Therefore, the fabricated two-axis force sensor can be used to measure the force of ankle lower part in the walking assist robot.

스테인레스 봉입형 반도체 압력센서의 제작 및 그 특성

김우정,조용수,황정훈,최시영 한국센서학회 2002 센서학회지 Vol.11 No.3

스테인레스 봉입형 압력센서를 제작하기 위하여 먼저 반도체 제조 및 식각 공정을 통하여 반도체 압력센서를 제작하였다. 그리고 이를 glass molding된 스테인레스 housing에 올려놓고 50 ㎛ 두께의 스테인레스 박판을 용접한 후 실리콘 오일을 채워 넣고 봉입하여 압력 범위 10 bar 센서를 완성하였다. 이와 같이 제작한 센서와 XTR105 발신기 전용 회로를 결합하여 4~20 mA 출력의 압력 발신기를 제작하고 그 특성을 조사하였다. 온도 보상 전 정확도는 ±5% FS이었으나 보상 후 정확도 ±1% FS로 개선되었다. The silicon piezoresistive pressure sensor is made by semiconductor process to obtain stainless steel isolated type pressure sensor. The sensor is loaded on a stainless steel housing with glass molding, 50 ㎛ stainless steel thin film is welded, and the stainless steel housing encapsulated by silicone oil. The performance of fabricated the pressure sensor has 10 bar pressure range. The XTR105 of exclusive transmitter chip is used the pressure transmitter that output current is 4 - 20mA. The accuracy is ±5% FS, however, the accuracy is ±1% FS when the sensor is compensated temperature.

상지재활로봇의 팔힘측정용 2축 힘센서 설계

김갑순 ( Gab Soon Kim ) 한국센서학회 2015 센서학회지 Vol.24 No.2

This paper describes the design of a two-axis force sensor with two step plate beams for measuring forces in an upper-limb rehabilitation robot. The two-axis force sensor is composed of a Fz force sensor and a Ty torque sensor. The Fz force sensor measures the force applied to a patient’s arm pushed by a rehabilitation robot and the force of patient``s arm. The Ty torque sensor measures the torque generated by a patient’s arm motion in an emergency. The structure of sensor is composed of a force transmitting block, two step plate beams and two fixture blocks. The two-axis force sensor was designed using FEM (Finite Element Method), and manufactured using strain-gages. The characteristics test of the two-axis force sensor was carried out. as a test results, the interference error of the two-axis force sensor was less than 1.24%, the repeatability error of each sensor was less than 0.03%, and the non-linearity was less than 0.02%.